Tuesday, April 24, 2018

With the new experiment, the US space agency wants to research how human sperm cells react to microgravity — and whether humans could procreate in space. Other mammals have had little success so far.

"As we plan to travel beyond the space station with thoughts of colonization on the moon and Mars and other heavenly bodies, the question of whether or not multi-generational survival can occur — not only in animals but in humans — is a very fundamental question that needs to be addressed,"

...In mammals, including humans, fertilization occurs when a sperm cell swims toward and enters an egg cell. For this to happen, though, the sperm must be "activated" first, otherwise it won't get moving at all. Next, the sperm cell has to pick up speed to be able to fuse with the egg cell, and the sperm's cell membrane has to become more fluid.

Previous experiments in space with bull or sea urchin sperm showed that while sperm was activated faster in microgravity, the subsequent steps happened slower or not at all.